    lv_obj_set_style_pad_all(struct _lv_obj_t * obj, lv_coord_t value, lv_style_selector_t selector)
    /*这个函数是设置4个padding距离*/
   lv_obj_set_style_pad_left(struct _lv_obj_t * obj, lv_coord_t value, lv_style_selector_t selector)
   /*这个函数是设置左边padding距离*/



    lv_obj_t *parent = lv_obj_create(lv_scr_act());
    lv_obj_set_size(parent,100,100);
    //设置内边距
    lv_obj_set_style_pad_all(parent,0,0);
    //设置颜色
    lv_obj_set_style_bg_color(parent,lv_palette_main(LV_PALETTE_BLUE),0);
    lv_obj_align(parent,LV_ALIGN_CENTER,0,0);

    lv_obj_t *child = lv_obj_create(lv_scr_act());
    lv_obj_set_size(child,50,50);
    lv_obj_set_style_bg_color(child,lv_palette_main(LV_PALETTE_GREEN),0);
    lv_obj_align_to(child,parent,LV_ALIGN_BOTTOM_MID,0,0);
